Implement integration and end to end tests

[walnut-the-cat]

• Manually control amount of chunk endorsements set; check that if 1/3 or 1/3 + 1 endorsements are not sent then shard is (isn’t) making progress
• State witness distribution logic, similar to chunks management tests: reconstruction, forwarding
• Check that heavy txns load doesn’t disrupt chain and state witness size is still limited. Tx is heavy if it tries to generate huge storage proof, its size is big, maybe in other cases.
• Same but simulate long missing chunk ranges (with congestion control in place)
• Check that shards are not shuffled if validators don't go offline
• Add test with invalid chunk proposed by a chunk producer nearcore#11331
• Check case when source receipt proofs are huge